Method of preventing the formation of scale



LLOYD 1,916,677

METHOD OF PREVENTING THE FORMATION OF SCALE Filed Aug. 28, 1931 vjnvenfor: 5 JbH/v LL 0Y0 Patented 4,.1933

UNITED STATES PATENT. o Frcs I 3031f LLOYD, NORTH BBADDOCK, PENNSYLVANIAm0!) 0] PREVENTING THE I'OmTION OI SCALE Application fled lngult 88,1881. Serial I0. @604).

through the nozzles 3. Valves 13 and 14 may This invention relates to amethod of preventin the adherence of scale to metal forming ro s. It iswell known thatwhen metal is heated ,to rolling temperature metallicoxids-are formed on its surface in the form of a scale and that whensuch metal is passed through a rolling mill this scale sometimes adheresto the rolls thereof and leaves marks on the finished metal. Thisinvention is characterized by the fact that a secondary surface ismaintained between the mill rolls and. the metal being formed thereby,this preventing the adherence of scale to a marked degree. This ispreferably accomplished by continuously bathing the rolls with a'coafluid during the rolling operation. Suc a coating fluid may be coppersulfate, potassium chromate, etc.

The accompanying drawing schematically represents one form of apparatuswhich may be used in the performance of the method incor orated in thisinvention. aving reference to this drawin there is shown a stand ofmetal rolls 2 for t e formation of a railroad rail. A double nozzle 3 isarranged over the top roll to thoroughly spray fluid over its rollingsurface, this nozzle being connected through a pipe line 4 to a tank 5and steam line 6. This steam line 6 is in connection with the top oftank-5 through a line 7 so as to equalize the pressure in this tank, thewhole arrangement acting simply as 4 an atomizer.

The tank 5 is filled with a coating fluid,

through the funnel ended inlet 8, so that when steam is turned on thematerial will be ejected through the nozzles 3 in the form of a spray. Asecondary surface may thus be maintained between the top 1-0112 and themetal being shown would probably include a gage 9 for indicating theheight of the material in the tank 5, and valves 10 and 12 would beinter- V. posedin thelinesd and 7 at the a g ints indicated to efiect acontrolof t e relative amounts of-steam coating fluid ejected also beadvanta eously inserted in the inlet 8 and the steam inc 6 for obviouspur oses. It might be added that the present speci' e description anddrawing is in accordance, with the patent statutes, and not with theintention of limiting the scope of this invention ex-' actl thereto,except as is defined by the appen ed claims.

I claim:

1. The method of preventing the adherence of scale to the surfaces ofsha'ped rolls in hot rolling ferrous metal shapes yvhich consists mmamtamin a secondary surface onsaid rolls during the scale isnon-adherent.

e rolling operation to which 2. The method of preventing the adherenceof scale to the surfaces of shaped rolls'in hot rolling ferrous metalshapes which consists in maintaining a seconda surface com of a coatingof a chemi a1 salt on sai rolls during the rolling operation to whichthe scale is-non-adherent.

3. The method of preventin of scale to the rolls of a hot-mi 1,consisting in continuously spraying the rolls with a metallic saltsolution, whereby a secondary surface is maintained between the rollsand the metal the adherence

